1. Field of the Invention
The present invention relates to an illumination device and a communication system.
2. Description of the Related Art
Various position information management systems have been proposed to acquire a position(s) of a person and/or a thing in a facility where it is difficult to carry out precise positioning using the Global Positioning System (GPS). For example, a system has been proposed to acquire a position of a person or a thing by attaching a Radio-Frequency IDentification (RFID) tag thereto from which information is readable by radio.
International Publication No. 2005/086375 (Patent Reference No. 1) discloses a system in which a radio terminal receives unique information transmitted by an illumination device and transmits the unique information to a server, whereby the position of the radio terminal is determined.